Engine starter gearing



June 29,1943. D, P, KEARNEY 2,322,964

ENGINE STARTER GEARING Filed March 13, 1942 Patented June 29, 1943 UNITED STATES PATENT OFFICE 2,322,964 ENGINE STARTER. GEARIN G Daniel P. Kearney, Birmingham, Mich., ass'ignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware 1 Application March 13, 1942, Serial No. 434,522

4 Claims gearing and more particularly to that type of automatically engaging drive in which the gearing is held in mesh until the engine is reliably self-operative.

In the patent to Kearney, No. 2,218,972,211; drive 7 is illustrated which utilizes a centrifugal latch cooperating with an abutment on a screw shaft for holding a pinion in engagement with an engine gear. This arrangement has been foundto I successfully maintain the cranking connection until the connection is intentionally broken by the operator, but under somecircumstances it may be preferable to utilize some other abutment than the screw shaft for maintaining the pinion.

in mesh.

It is an object of the present invention to provide a novel starter drive of the above type which is efficient and reliable in operation and simple and economical in construction.

It is another object to provide such a device which incorporates a latch cooperating with an abutment on a housing for holding the pinion in mesh with the engine gear.

It is another object to provide such a device having an overrunning connection to the pinion permitting the pinion to rotate faster than the starting motor when the engine starts.

Further objects and advantage will be apparent from the following description taken in connection with the accompanying drawing in which:

Fig. 1 is a side elevation partly broken away and in section of a starter drive incorporating a preferred embodiment of the invention.

Fig. 2 is a section taken substantially on the line 22 of Fig. 1 showing the latch in normal or idle position; and

Fig. 3'is a view similar to Fig. 2 showing the latch in operative position.

In Fig. 1 of the drawing there is illustrated a housing l which may be an extension of the housing of a starting motor not illustrated. A power shaft 2 is journalled in the housing I and has fixed thereon in any suitable manner a sleeve 3 having a driving head 4 at one end and a stop nut 5 at the other. A screw shaft 6 is slidably journalled on the sleeve 3 between the drive head and stop nut and has a driven head 1 which is connected for rotation with the driving head 4 by means of a spring 8, the ends of which are attached to anchor plates 9 and H non-rotatably mounted on the driving and driven heads respectively.

A pinion I2 is slidably journalled on'the power (01174-7) .The present invention relates to engine starter shaft 2 for movement into and out or engage- ,ment with a member such as a gear -I 3 of an engine to be started, and means for traversing and rotating the pinion from the screw shaft 6 is provided in the form of a nut M on the screw shaft and a barrel l5 rigidly connected to the nut and having .,a swivelled overrunning clutch connectionwith the pinion. As here shown, this connection comprises an inturned flange It on the barrel formed with ratchet clutch teeth adapted to engage corresponding ratchet teeth on a, driven clutch member IT fixed to the pinion shaft is rotating above a predetermined speed.

As'he're shown this means coinprises an abutment in the housing in the form of a ring 2|, and a latch member 22 pivotally mounted on the nut I4 as by mean of a pin 23, normally maintained in retracted position as shown in Fig. 2 by means of a spring 24, but arranged to move out into position to engage the abutment 2| as shown in Fig. 3 when rotated above a predetermined speed.

Means for returning the parts to idle position and normally maintaining the pinion de-meshed is provided in the form of an anti-drift spring 25 interposed between the nut I4 on the screw shaft and the stop nut 5 on sleeve 3.

In operation, starting with the parts in the positions illustrated in Fig. 1, rotation of the power shaft 2 is transmitted through sleeve 3 and spring 8 to the screw shaft 6, causing the nut M to be traversed along the screw shaft, moving the pinion 2 into engagement with the engine gear I3. When the nut Id engages the stop nut 5, the longitudinal movement of the pinion and barrel assembly is arrested and the parts are constrained to rotate with the power shaft, thus causing the engine to be cranked. When the engine starts, the pinion I2 is accelerated by the engine gear l3 and overruns its driving connection by disengagement of clutch members l6, H. The consequent release of the load on the starting motor causes rapid acceleration of the drive including the nut M. The latch 22 mounted thereon is thus caused to move out into the position illustrated in Fig. 3 where it is positioned to engage the abutment ring 2| in the housing I which consequently prevents ole-meshing movement of the pinion and barrel assembly. This situation continues as long as the starting motor remains energized, and if the engine should not continue to be self-operative it will slow down sitions with the assistance of the frictional torque transmitted through the overrunning clutch members It, I1.

It will be appreciated that inasmuch as there is relative motion between the latch 22 and the abutment 2| at all times during the operation of the drive, there is no possibility of sticking of the parts and the arrangement of the abutment in the housing permits the incorporation of the invention in existing types of drive with minimum alteration of the parts of the drive.

' Although but one embodiment of the invention has been shown and described in detail, it will be understood that other embodiments are possible and that various changes may be made in the design and arrangement of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In an engine starter a housing, a power shaft, journalled therein, a screw shaft driven from the power shaft, a nut on the screw shaft, a pinion slidably journalled on the power shaft, means including an overrunning connection, for traversing and rotating the pinion from the nut, said housing having an abutment, and a centrifugal latch mounted to rotate with the nut engageable with said abutment for preventing traversal of the nut.

2. In an engine starter a housing, a power shaft journalled therein, a pinion slidably journalled on the power shaft for movement into and out of engagement with a member of an engine to be started, actuating means for the pinion including a member having an overrunning clutch connection therewith, said housing having an abutment, and centrifugal means on said member adapted to engage the abutment to prevent 10.

longitudinal movement of said member to disengage the pinion.

3. In an engine starter a housing, a power shaft journalled therein, a pinion slidably journalled on the power shaft for movement into and out of engagement with a member of an engine to be started, actuating means for the pinion including a screw shaft connected to rotate with the power shaft, a nut on the screw shaft, a barrel fixed to the nut, an overrunning clutch connection between the barrel and pinion, said housinghaving an abutment and means on the barrel engageable with the abutment to hold the barreland pinion in operative position.

4. In an engine starter drive a housing, a power shaft journalled therein, a pinion slidably'journalled on the power shaft for movement into and out of engagement with a member of an engine to be started, means whereby rotation of the power shaft traverses the pinion into operative position and then rotates it to drive the engine member, said means including a barrel member having an overrunning clutch connection to the pinion, an abutment in the housing surrounding the barrel, and a centrifugal latch on the barrel adapted to engage the abutment and hold the barrel in operative position as long as it rotates above a predetermined speed.

DANIEL P. KEARNEY. 

